feat: linux: Add compilation instructions for EdgeAI GUI App

meta-arago-toolchain lacks Qt6 support for compiling EdgeAI GUI App.
The correct way to compile it is to use Yocto.

However, for quicker way to compile it, we can also use ARM64 Docker
containers. Provide a guide on how to compile edgeai-gui-app using
ARM64 Docker container which TI provides [0].

[0] https://github.com/TexasInstruments/ti-docker-images/pkgs/container/debian-arm64

Signed-off-by: Suhaas Joshi <s-joshi@ti.com>

Author: jsuhaas22

source/linux/Demo_User_Guides/Edge_AI_Gallery_User_Guide.rst

@@ -139,3 +139,44 @@ The edge AI gallery launches on Linux startup. Follow the below instructions to
 .. ifconfig:: CONFIG_part_variant in ('J784S4')
 
    13. For more information on edge AI software stack, refer `Edge AI Documentation <https://software-dl.ti.com/jacinto7/esd/processor-sdk-linux-edgeai/AM69A/10_01_00/exports/docs/common/sdk_overview.html>`_
+
+Compiling EdgeAI GUI App
+========================
+
+The ideal way to compile EdgeAI GUI App is to trigger a Yocto
+build. But for a quicker way to do it, especially during development,
+TI provides a `debian-arm64
+<https://github.com/TexasInstruments/ti-docker-images/pkgs/container/debian-arm64>`__
+Docker image. This image already contains all dependencies required
+for compiling edgeai-gui-app.
+
+First, clone TI Apps Launcher:
+
+.. code:: console
+
+   git clone https://git.ti.com/git/apps/edgeai-gui-app.git
+   export EDGEAI_GUI_APP_REPO="$(pwd)/edgeai-gui-app"
+   cd ${EDGEAI_GUI_APP_REPO}
+
+Then, pull TI's debian-arm64 Docker image and run it:
+
+.. code:: console
+
+   docker pull ghcr.io/texasinstruments/debian-arm64:latest
+   docker run -it -v ${EDGEAI_GUI_APP_REPO}:/root/ti-apps-launcher ghcr.io/texasinstruments/debian-arm64 bash
+
+Finally, run:
+
+.. code:: console
+
+   cmake -B build -S . -DRT_BUILD=0 # if target is RT image, make -DR_BUILD=1
+   make -C build
+
+The compiled binary should be ``build/edgeai-gui-app``.
+
+.. note::
+
+   This is a quick and easy way to compile ti-apps-launcher during
+   development, but it is a good idea to validate with Yocto builds
+   often. There is a possibility that compiler mismatch could present
+   issues in the run up to production.